Certain medical procedures, such as thrombectomy, angioplasty, and so on, require a catheter that is navigated through a patient's vasculature to a target site for treatment. The catheter has to have sufficient flexibility and column strength so that it may be torqued, pushed, and pulled on its way through the vascular passages to the target site within the patient's body. It is also preferable for the catheter to have a relatively small profile so that it can access narrow vasculature with minimal damage to surrounding tissue. In addition, a relatively small profile may be preferred so as to minimize the amount of polymer materials needed to manufacture the catheter.
In some cases, catheters with multiple lumens (also referred to as “multi-lumen catheters”) may be needed to allow fluid communication with the target site, and/or to allow another medical device such as a stent or balloon, for example, to access the target site. For some procedures, such as thrombectomy, a separate guidewire lumen may be desirable to guide the catheter to the target site, while the main lumen may be used for aspiration to remove blood clots and/or other debris from the target site.
In an example process, a multi-lumen catheter may be fabricated by joining two or more tubular members together, each having a wall thickness around its lumen. Joining the walls of the two tubular members increases the overall diameter of the multi-lumen catheter, thereby reducing the flexibility of the multi-lumen catheter.
One approach to reduce the profile of a multi-lumen catheter is to reduce the wall thickness of the tubes that are combined in fabricating the multi-lumen catheter. However, such fabrication of a thinner-walled multi-lumen catheter may not have sufficient column strength to easily navigate through tortuous vascular passages. For example, kinks may develop during navigation and/or one or more lumens of the catheter may collapse under external fluid pressure and/or internal vacuum created during aspiration.
Therefore, there is a need for an improved multi-lumen catheter that has a smaller profile with sufficient flexibility and column strength for easy navigation and adequate resistance to radial collapse.